Mississippi
General patterns from public USGS groundwater research, not a prediction for your specific well. Depth, local bedrock, and nearby land use matter more than the state line.
Nitrate from fertilizer, livestock operations, and septic systems is the best-documented contaminant risk in wells across the region's agricultural areas, per long-running USGS groundwater monitoring.
A test is the only way to know what's in your well. Already have results? Upload them and get every reading checked against EPA levels, free.